Automatic telephone system



Dec. 29., 1925- 5 1,567,309

| R. WALLER AUTOMATIC TELEPHONE SYSTEM Filed Oct. 1'7 1923 4 Sheets-Sheet 2 l8 A I i me 5 52a I40 5P4 MARG/Ml 23 hvenfor:

Lee R Waflen Dec. 29, 1925- 1,567,309

r L. R. WALLER AUTOMATIC TELEPHONE SYSTEM Filed Oct. 1'7, 1923 4 Sheets-Sheet hu /1hr.- ee A. (d/kl. f pi,

1,567,309 L R WALLER AUTOMATIC TELEPHONE SYSTEM Filed Oct. 17, 1925 4 Sheets-Sheet 4 0 I I I I I. I m 0 I I I I I m 7 Dec. 29, 1925- w m I hvewlbn- L e F?! Wa//e/r Patented Dec. 29,, 1925.

nsist UNITED STATES PATENT orricn.

LEE R. WALLER, OF WESTMOUNT, CANADA, ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. 'Y., A CORPORATION OF NEW YORK.

AUTOMATIC TELEPHONE SYSTEM.

Application filed October 17, 1923.

To all whom it may concern:

Be it known that I, Lee R. WALLER, a citizen of the United States of America, residing at Westmount, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic tele- "phone systems and particularly to exchanges and switches applicable therein.

The object of this invention resides in the provision of a telephone system of the private branch exchange type which will be simple, eflicient and-in which the number of switching devices required for extending telephone connections from calling to called lines are reduced to a minimum.

A. feature of'this invention is a cross-bar switch combining ina single structure the functions of a line finder, a register controller selector and a'connector. There are provided line bars'and register controller bars in parallel relation to each other and both incoming and outgoing link bars in coordinate relation with said other bars. All lines and register controllers are accessible to the incoming links and all lines are accessible to the outgoing links.

Another feature of this invention is a mechanical interlocking device for the register controller bars whereby one register controller is held inpreselected condition and the others are locked against use.

Another feature of the invention resides in a cross bar switch in which the link or trunk bars have a normal and an operated position and the line bars have a normal, an operated and a busy position. The line bar, which is equipped with flexible contacts, is first moved to its operated position where the flexible contacts are in the path of the contact lugs on the trunk bar. Then through the operation of a line bar off normal device a trunk bar is'moved to its operated position. The contact lugs of, the trunk bar engage the flexible contacts of the line bar and through a toggle joint action of such flexible contacts move the line bar from its operated position through its normal position to its busy position wherein the multipled contacts are out of the'path of other trunk bar contact lugs.

Other features of the invention and ad- Serial No. 669,102.

vantages will appear from the following description and by the claims appended thereto, reference being had to the accompanying drawings in which:

Fig. 1 is a schematic diagram of the circuit arrangement employed in the telephone system.

Fig. 2 is a detailed circuit arrangement of said system.

Fig. 3 is a partial front assembly View of the cross bar switch used in said system.

Fig. 4C is a sectional view thereof, taken approximately on line A-A of Fig. 3 and viewed in the direction indicated by the arrows.

Fig. 5 is a sectional view taken approximately on line B-B on Fig. 3 and viewed in the direction indicated by the arrows.

Fig. 6 is a view similar to that of Fig. 4 but showing the lowermost situated line bar in operated position.

Fig. Tie a view similar to that of Fig. a showing, a trunk 'bar in operated position and the contacting lugs carried thereby in engagement with the contacting springs of a line and a preselecting bar.

Fig 8'is asectional view of said switch showing the preselecting bar interlocking mechanismr Similar reference characters refer to similar parts throughout the several views. .7 p

The telephone system shown in Fig. l broadly consists of a cross bar switch in which the operating mechanism is capable of being contr lled to connect telephone lines to trunks or trunks to telephone lines through the setting of rotary selector switches under control of calling devices at the substations.

The cross bar switch shown in detail in Fig. 8 generally consists of a supporting frame 20 in which the insulating line bars 11 are pivotally arranged and free to move a small angular distance in opposite direction to their normal non-operated position.

On one end portion of each bar 11 there is securely arranged an insulating stud 22 disposed in operable relation with a pair of contact springs 23 and 24 adapted to hold their respective associated bar 11 in normal non-operated position and to perform other switching functions which will be hereinafter described.

An insulating stud 10 securely arranged on a portion of the switch frame 20 is provided for holding the contact springs 23 and 24 in spaced relation, relative to each other and for assisting them in holding their respectively associated line bar 11 in normal position. Each line bar 11 carries a plurality of multipled sets of fiat contact springs 25 and 2G and an armature 27 adapted to rotate its respectively associated bar 11 against the resistance of spring 23 in response to each energization of an operating electromagnet 28. The sets of contact springs 25 and 26 are arranged in coordinate rows and extend obliquely from their supporting bar 11 in engageahle relation with the teeth 29 and 30 of two saw-toothed conducting strips 31 and 32 respectively. The conducting strips 31 and 32 are insulating ly held on two opposite sides of a longitudinally movable bar 33 which is disposed at right angles relative to the line bars 11 and is slidably arranged in the upper and lower portions of-the switch frame 20.

The switch structure may comprise any number of line bars 11 and any number of trunk bars 33 depending upon the switch capacity desired.

The trunk bars 33 are generally made of insulating material and are each provided with a number of teeth 34- and disposed in engageahle relation with associated retractingsprings and 3"! adapted to hold. the bars in normal non-operating position and to perform other switching functions which will be hereinafter described. The trunk bars 33 are each provided at one end portion with a duplex armature 38 adapted to move its associated bar 33 longitudinally in response to each energization of their respective associated pair of operating electromagnets 39 and 40 which are securely fastened on the right angle pole pieces 41 shown in Fig. 1 which in turn are secured on the switch frame 20 by any suit able means.

The trunk bars 33 are generally arranged into two equally divided grou s H and (B as shown in Figs. 1 and The group of trunk bars 1B are associated with preselecting bars 42 and which are pivotally arranged on the switch frame 20 and to he brought in selected position Mlill reference to their associated trunk bars 33 by means of a preselecting mechanism which will be hereinafter described.

Each preselecting bar 42 and 43 car plurality of sets of multiple contact springs 4d and 1-5 which extend obliquely therefrom in engageahle relation with their re spectively associated contacting lugs 4th and. 17. Such lugs are eenerally formed integrally with the conducting strips 4-3 and 49 which are insulatedly arranged on their respective trunk bars of the group IB. On one end of bar 1-2 there is pivotally arranged an arm 50 angular movement apted' of which is limited by means of stop pins 51 and 52 shown in 6 7 and 3. "llupins 51 and 52 are secured on a portion of the switch frame 20 and are adapted to hold the arm in engageable relatioi'i with its associated bar 4-3 against the resistance of an operating spring 53 which acts agaius the cam portion 54- of arm 50. Spring;- .33 is adapted to hold the bar 1-2 and the sets of contact springs and 4-?) served therelrv in preselecteil position with reference to their associated trunk bars 33 and for holding the urn) 50 in cngagcahle i'ciul'iou will: the face of the right angled portion 55 car-- ricd by the bar 13. On the hair 4-3 there is provided a stud which is in operahlrrelation with a retracting spring 5i" adapted to hold the bar 43 in preselected position against the stop pin which is securely held on a portion of the switch frame 20.

41- and 6 show the bar sir-2 iii pm 1,-- lected position and the contact sprini and s5 carried thereby in engageahlc tion with their respectively associated tacting lugs 51:6 and 17. YVhen har ei-EZ in preselected position bar 13 is locked in neutral position through. the enga' iucut o arm 50 with the shoulder 55 of bar and the stop 51 adapted to resist the action of spring 57 acting against the stud 36. \Vhcn the associated trunk bar 33 is moved in operated position, as shown in Fig. 7, the toggle joint movement of the engaged contact springs daland 4-5 rotate the her 42 a small angular distance against the resi ance of spring 53 for moving the issocie. ,c-il of contact springs a l and h) carried thereby out of operable relation with the other trunk bars 33 of the group [B and unlatches the bar 4-3 which is rotated in we selected position against the stop 58 by means of spring 57.

Arm 50 is then. rotated at small angular distance through the action of spring 53 acting against the cam portion of arm :30 and the bar 42 together with the contact springs and 45 are locked in neutral position with reference to their associated trunk .i-ars 33 through the engagement of arm 50 with the top of the shoulder if of bar The hars 42 and 1-3 are each provided with armatures 59 and 60 adapted to rotate their res cctively associated bar 42 and i and the contact springs and carried thereby in response to eachv energi :aation of electroniagncts 1 and G2 which are ada t ed fo disengaging the contact springs 4-]- and from the c noting lugs -16 and 4-7.

Fig. s ovcs the operating circuit '::ii teinplated n in connection with l ahoie den a however that th varioiis sets of man: is and 40 shown in lig. -t as associati d with each trunk car are represented in Fig. L?

the designations CB IE and 18 et Since the windings of magnets 39 and are connected in series, each set in r ity constitutes a unitary magnet, and for the sake of simplicity these magnets are shown in Fig. 2 as having but a si gle Winding. The manner in which the sw ch tunctions to interconnect calling and called lines will now be described: The removal of the receiver at the calling station 101 close circuit for its associated line bar et 28 from tree pole of battery, upper armature and normal contact of magnet CB cor ductor 102, upper arnia" and no tact of magnet 1B conductor 1022', upper armature and normal contact of ma ct 1B conductor 10%, contacts 98 and ill, conductorfil), Winding out magnet normally closed contact springs 1053 and 1 conductor 10?, the subscriber s set 101, c,

ground. Magnet 28 energizes 1V therehy in engageable relation with the teeth 29 and 30 of trunlr bars of the and CB groups. lhe movement of the line bar 11 in its counter-cloclnvise direction. closes a circuit for slow releasing relay fil through contact springs 11]. and 112, norn tor 11d, inner armature and normal of relay 1B Winding cl" relay ground. This relay operates and counsel battery to magnet 1B Magnet e gizes and operates its assoc ed tr in the group The me. t or engages the contact spring and A) or the calling line bar with conducting 31 and and conned the conducting st 48 and to the contact springs -L 1 of a preselected bar in a manner here a tore stated. Due to the toggle joint moveline bar 11 is rotated in a cloci tion and the idle contact sprin i carried thereby are moved o. i position from the idle trunk bars circuit is now closed for t Wi... c

ing relay lilld from ground its left hand Winding, the ii. l: 1% condo. ing strip 31, in contact with the contact g conductor 10? oi the line ba the subscrioers set 101, con or 0' line bar 2-1, contact spring 520, in with the. strip 52, right hand windi lay DP. to ground. Relay one this circuit and applies battery for slow relay tilt energized. When its circuit is opened by the operation of contact Spffl lll when the line bar 11 is moved clockwise through the operation of trunk bar lt here noted that upon the energization 01'' magnet 28, stud moves down- Wardly so that connection is made between enough to hor r used While t hen pole of battery, winr 0 @Olllittl s mature and front contact of relay ground. Relay SP energizes in this not and applies ground for relay SP Wl'iich on 3d prepares a circuit slow rem ing relay SP and the motor magnet f. of the rotary si The impulse circuit for rotary switch BS is now completed and upon the operation of the calling device 100 at the calling station 101, the line circuit is interrupted causing impulses to be repeated by relays Dllt and SP to motor magnet Mlrl of the rotary switch through the lower Winding of relay SP which becomes energized. lit the first digit dialled is 1, the rotary switch is moved one step, relay SP deenergizes and closes a circuit for relay SP through ground, lower armature and normal. contact of relay SP conductor 116, the first contact cooperating With the brush RS conductor 117, Winding of relay SP to battery and ground. Relay SP energizes in this circuit and closes a circuit for motor magnet MM through grounded battery, winding of motor magnet MM, its own armature and break contact, conductor 118, the first contact cooperating with brush RS its multiple contacts, conductor 119, upper armature and front contact of relay SP to ground. Motor magnet MM operates in this circuit and rotates the brush-set twelve steps to contact with the terminal 120, relay SP remaining locked through the brush RS 3 until the switch has reached its thirteenth contact. The next operation of the dial Will carry the switch to the desired line.

lit the first digit dialled is 2, relay E51 does not energize and the brushes Will rotate two steps and stop. The second operation of the dial Will cause the switch to select the called line.

Assuming that a subscriber at station 101 desires to call a subscriber Whose station is No. 21 and that it is not busy, a circuit Will be closed for magnet 28 of the calling line bar, through free pole of battery, upper armature and normal contact of connecting bar magnet CB conductor 102,

upper armature and normal contact of magnet 1B conductor 103, upper armature and normal contact of trunk bar magnet 1B conductor 104, winding of magnet 28, of the called line, conductor 119, the third con tact of RS, its respectively associated brush, conductor 145, lower inner armature and normal contact of relay SP conductor 121, inner armature and normal contact of relay SP winding of relay S1? to ground. Relay SP is marginal and does not operate in series with magnet 28. A circuit is also closed for relay 113 through free pole of battery, winding of relay 113, conductor 122, the third contact of RS, its respectively associated brush, conductor 123, lower armature and normal contact of relay SP, the middle armature and normal contact of relay SP conductor 124, lower armature and normal contact of relay SP to ground. When the line bar of the called line No. 21 is moved by magnet 28 into engageable relation with the trunk bar 33 of the terminating group CB a circuit is closed for magnet CB through free pole of battery, upper armature and front contact of connecting bar magnet CB conductor 102, upper armature and normal contact of trunk bar magnet 1B conductor 103, upper armature and normal contact of trunk bar magnet 1B conductor 104, springs 111 and 112, armature and trout contact of relay 113, conductor 125, the third contact of RS, its respectively associated brush, conductor 126, the contact spring 45, in'engagement with the conducting strip 48, conductor 128, winding of connecting bar magnet CB to ground. Magnet GB in energizing operates the connecting trunk bar 33 in the group CB and locks through the free pole of battery, armature and front contact of slow relay SR, conductor 129, lower armature and front contact of magnet CB its own winding to ground.

The movement of the connecting .bar 33 engages the springs 25 and 26 at the called line bar 21 which is thereby rotated a small angular distance in opposite direction for closing the contact 130 to place a short circuit around relay 28 thus permitting relay SP to operate. Relay SP in operating closes a circuit for magnet 61 which energizes and rotates its associated preselecting bar 42 to disconnect the Contact springs 44 and 45 carried thereby from the trunk bar 33. Relays SP and SP release due to the removal of the ground through the disengagement of spring 44 from conducting strip 49 and permit the restoring of the rotary switch through the ground placed in the circuit of the motor magnet MM when relay SP releases its armature. Relay S1 releases when the rotary switch reaches its normal position shown in Fig. 2.

When the called line bar No. 21 connects with the connecting trunk bar 33, ringing current is intermittently applied to the called. station by relay RR and when the called party answers by removing his telephone receiver from the switchhook, relay DR energizes and cuts off the ringing currentthrough the breaking of contact 147 by the attraction of its outer left hand armature. Relay DB remains energized through its right hand holding winding connected to conductor 129.

In case a busy line is called, relay SP" will operate to disconnect the preselected springs and 45 without operating the terminating magnet and the calling station 'ill then hear the busy tone which is normally connected to the links as shown at 146 in Fig. 2.

It should be noted that normally lines numbered 21, 22 and 23 have access to the link circuit shown, this being an indication of the arrangement provided for as far as possible evenly distributing the trafiic over the various links. An examination of the contact arrangement for brushes RS and RS will show the preferred arrangement herein employed.

\Vhat is claimed is:

1. In an automatic telephone system, the combination of line bars, a first and second group of trunk bars associated with said line bars, subscribers line circuits normally connected to said line bars, impulse senders in said line circuits, preselecting means for selectively associating one of said line bars with one of said first group trunk bars, and rotary switches operable under control of said senders for selectively connecting one of said second group trunk bars to another of said line bars for establishing telephone connections therebetween.

2. In a telephone system, the combination with subscribers lines, impulse senders associated with each of said lines, a switching device for interconnecting said lines, trunk bars of dilierent characters in said device arranged by pairs, link conductors for each of said pairs, electromagnets for individually operating said trunk bars, impulse registers associated with said device for selectively controlling the extension oli connections from a calling to a called line, an impulse circuit therefor, presclecting means for ass ciating one of said registers with a calling line circuit, and means for disconnectin said preselecting means when the caller line subscriber answers.

In a switching device, the combination of line bars, magnets for positioning said bars, groups of trunk bars of different character associated with said line bars, sets of preselecting bars associated with the trunk bars of one group, sets of contact springs carried by each of said preselecting bars,

one set for each of said trunk bars, a latching member carried by one of said preselectnets for rotating said bars in one direction,.

a plurality of trunk bars disposed at right angles relative to said line bars, conducting strips insulatedly arranged on each of said trunk bars, contacting projections carried by each of said strips for operatively engaging said contact springs, means for rotating said line bars in another direction to move the idle springs carried thereby in position wherein the operation 0t another trunk bar is ineffective to interengage the last mentioned springs, and means for rotating the line bar to normal position when the trunk bar is released.

5. In a cross bar switch, the combination of line bars, trunk bars disposed in engageable relation therewith and arranged by groups, incoming trunk bars in one of said groups, outgoing trunk bars in the other of said groups, link conductors normally connected from trunks in one group to similarly disposed trunks in the other group, other bars associated with said incoming bars, sets of contact springs carried thereby, and a preselecting mechanism for connecting said. other bars in engageable relation with said incoming trunk bars.

6. In a cross bar switch, the combination of a group of trunk bars, a preselecting mechanism comprising a pair of rotatable bars. a latching member carried by one of said bars, an angular shaped cam carried by the other, means for moving said member in engageable relation with said cam for lockins said other bar in non-operated position with reference to said trunk bars, means for moving said latching member for unlatching the second mentioned bar when one of said trunk bars is operated, means for rotating said other bars in preselected position and for locking the first mentioned bar in non-operated position with reference to said trunk bars by means of said cam, and electromagnetic means for disengaging said bars from said trunk bars individually.

7. In a telephone system, telephone lines, link circuits. register controllers and a cross bar switch for interconnecting said lines through said link circuits under control of said register controllers, said cross bar switch comprising line bars. link bars and register controller bars. said line bars and said register controller bars being arranged in parallel relation with each other, said link bars being arranged in coordinate rela tion with said other bars, said link bars being further divided into two groups, one group being connected to the incoming end of said link circuits and arranged to estab lish connections to said linesand said register controllers and the other group being connected to the outgoing end of said link circuits and arranged to establish connections to. said lines, and a mechanical interlocking device for said register controller bars for rendering said register controllers successively accessible.

8. In a cross bar switch, a trunk bar having a normal position and an operated position, a line bar having a normal. position, an operated position and a busy position, means for moving said line bar to its operated position, means responsive thereto for moving said trunk bar to its operated position, and means responsive to the movement of said trunk bar for moving said line bar out of its operated position into its busy position.

9. In a cross bar switch a trunk bar having a normal position and a busy position, a line bar having a normal position an operated position and a busy position, contact lugs on said trunk bar, flexible contacts on said line bar cooperating with said contact lugs, means to move said line bar into its operated position whereby said flexible contacts are moved into the path of said contact lugs, and means responsive thereto for moving said trunk bar into its operated position whereby said contact lugs engage said flexible contacts and thereby move said line bar out of its operated position and into its busy position.

10. In an automatic telephone system, the combination with a plurality of tele phone lines, of a switch controlling register, and a unitary switching device having a plurality of bars cooperating with one another to connect any one of said lines with said register and for connecting said one of said lines with any other of said lines.

11. In an automatic telephone system, the combination with. a plurality of calling lines and a plurality of called lines, of a switch controlling register, and a unitary switching device having a plurality of bars cooperating with one another to connect a calling line with said register and for connecting said calling line with any of said called lines.

12. In an automatic telephone system, the combination with a plurality of calling lines and a plurality of called lines of a switch controlling register, and a switch having links and a plurality of sets of intersecting bars, certain of said bars being adapted to connect a calling line with said register and other ot said bars being adapted to connectsaid calling line with any of said called lines by means of one ot said link circuits,

13.111 an automatic telephone system, the combination with a plurality of calling lines and a plurality of called lines of an impulse register, a selector SWltCl'l comprising line hars, link ears and other bars, means controlled by a calling line and one of said other bars for setting said register to control the selective operation of said switch to connect said calling line with one of saidcalled lines, said'operation comprising the actuation of a line -barand a plurality of link bars! 14. In an automatic telephone system, the combination with a plurality of calling lines and a plurality of called lines, of a switch controlling register, a selector switch comprising line bars, link bars and other bars, means responsive to the initiation of a call on any one of said calling lines for causing said switch to operate to associate said calling line with said register and to actuate a line bar and a link bar, means under control of the calling 'line for variably plurality of switch controlling 17c settin said re iistcr to cause the actuation b n D or another of said link bars to thereby lillei-connect said callinn' line and a van-hauler H 1 o one or ca tiQ-(l lines.

15. In i automatic telephone a; can the comhniation with a plurality of '-'.liEH f lines and a plurality ot' ra led lineoi and a unitary swiwhing' dericc ha y plurality of bars opcrati with one :1- othcr to connect any one oi ud calling mica with an idle one of said registers and for connecting said one of said cailing lines with any of said called lines.

16. In an automatic telephone system. the combination with a plurality of calling); lines and a plurality of called lines, ol' 1: plurality of switch controlling registers and a'swit-ch having link circuits and a plurality of intersecting bars arranged to connect a calling line to a link circuit and to an idle register and to connect said linh' circuit to a called line under control of said idle register.

In witness whereof, I hereunto subscribe my name this 9th day of Oct. A. ll, i995).

LEE R. VVALLER. 

